Headlights and turn signals, part two

It has been put forth that automobile “headlights”, to which reference was previously made, are not headlights at all but are “running lights”. In light of that (pun intended), please now see the  pair of photographs in Figure 1: They are still images taken from a video clip.

Figure 1 Two Photographs of a turning automobile where the white lights in one headlight stays on while the other one (with an active turn signal) turns off. Source: John Dunn

These quick succession images were taken on April 17, 2023, at 1 PM while the weather was overcast and cloudy. However, I have seen exactly the same situation depicted above unfold on other occasions, well after sunset with the sky pitch black.

The white light as shown above, which remains lit without interruption, appears to be the output of a headlight. If it is instead a running light, the danger cited here arises anyway.

It should be noted that most cars, to my own observations, do not change the state of their white lights when turn signals are activated, only a few of them do. However, when the white lights of one side of those few vehicles do go dark, much needed illumination of the upcoming vehicle path can be markedly diminished which is very dangerous.

This is only the first peril meriting our concern. There is another as well.

A white light that is glowing all by itself on just one side of a vehicle as depicted above could, if only for a moment, be mistaken by a momentarily stressed and distracted driver of another vehicle as being the single white light of a bicyclist or a motorcyclist. The danger of such a misidentification should be self evident, but to vehemently stress that point, we will go further.

The following vehicle misidentification story dates back to the mid-1960s and was told to me in 1968 by one of my then co-workers. Be warned in advance that it may be very upsetting. Be prepared.

Please see this picture of a vintage Lincoln Continental in Figure 2 extracted from this URL and note the very wide separation between the two sets of headlights. When being driven with the high beams off, only one bulb on each side of the vehicle’s front end gets lit. In the dark at night, these two widely separated lights can be mistaken for two widely separated, side by side vehicles instead of the single vehicle it actually is.

Figure 2 A 1960 Lincoln Continental with a wide separation between two sets of headlights. Source: curbsideclassic.com

A gang of motorcyclists once spotted one of these cars coming toward them on a particularly dark night and they misidentified the widely spaced headlights of an oncoming Lincoln as being two separate lights of two separate oncoming motorcycles.

One of the gang members decided to scare what he thought were two oncoming motorcyclists by riding his own motorcycle head on at high speed straight in between the supposed pair of oncomers.

The story ends there.

John Dunn is an electronics consultant, and a graduate of The Polytechnic Institute of Brooklyn (BSEE) and of New York University (MSEE).

Related Content

The headlights and turn signal design blunder
Hurricane Ian and EV fires
A new EMI threat?
Automotive electronics vs Minnesota winters
The ‘too brights’







googletag.cmd.push(function() { googletag.display(‘div-gpt-ad-native’); });

The post Headlights and turn signals, part two appeared first on EDN.

0 replies

Leave a Reply

Want to join the discussion?
Feel free to contribute!

Leave a Reply

Your email address will not be published. Required fields are marked *